Many wheeled and crawler type vehicles today are provided with stabilizing outriggers. In the usual case, the vehicles serve as a means of transport for some sort of tool such as a backhoe, a crane or hoist, a ladder or the like that is carried by the vehicle frame to be transported thereby to a place of use. When the vehicle has travelled to the location of use, the outrigger stabilizers are caused to engage the ground, typically on opposite sides of the vehicle and typically at locations outboard of the wheels or tracks of the vehicle so as to prevent tipping when the tool carried by the vehicle is operated and is under load.
Because the outrigger stabilizers are not used when the vehicle is in transit, it is customary to provide a means for retraction of the outrigger stabilizers. One common construction that includes provision for such stowage involves the use of elongated outrigger arms having inboard ends and outboard ends. The inboard ends are pivotally connected to the vehicle frame so that the arms may be rotated about a generally horizontal axis.
The outboard end of the arm is pivotally mounted to a stabilizing shoe which, in the usual case, has a substantially flat, ground engaging surface of substantial area. In many instances, this surface may be provided with cleats as is well known.
The assemblage is completed by a hydraulic cylinder for each arm. Typically, the hydraulic cylinder will have its rod end connected to the outrigger arm near, or at, its outboard end. Usually, a pivot pin is employed to connect the shoe to the outboard end of the outrigger arm and this pivot pin forms a convenient means for securing the rod end of the hydraulic cylinder to the outrigger arm as well.
The cylinder end of the hydraulic cylinder is then pivotally connected to the vehicle frame, usually at a location above the inboard end of the outrigger arm. As a consequence of this construction, retraction of the cylinder will pivot the arms inwardly toward the vehicle frame and lift the shoes out of engagement with the underlying terrain. That is to say, retraction of the cylinder results in the outrigger stabilizers being moved to a retracted position for vehicle travel.
Conversely, extension of the cylinders causes the arms to be lowered to engage the shoes with the underlying terrain.
Typically, the vehicle has some sort of operator location whereat an operator of the vehicle may be disposed in the presence of controls for the tools carried by the vehicle as well as for the hydraulic cylinders that operate the outrigger stabilizers. In many instances, this operator location will be the same location whereat the operator is disposed to operate the vehicle in transit.
In any event, because of the need for stabilization of the vehicle as well as the need to readily stow the outrigger stabilizers when the vehicle is in transit, hydraulic controls for the outrigger stabilizers are highly desirable. At the same time, because of the expense involved in providing the requisite hydraulic circuits and components, it would be highly desirable if the same hydraulic components and circuits could be utilized to perform useful functions other than vehicle stabilization as well as the vehicle stabilization function for which they were designed.
The present invention is directed to achieving that result.